1. Field of the Invention
The present invention relates to a loudspeaker and more particularly to a high-frequency loudspeaker using a spherical or hemispherical vibrator.
2. Description of the Related Art
FIG. 5 is a partially cutaway perspective illustration of one example of conventional loudspeakers. A loudspeaker 1 using a spherical or hemispherical vibrator has been proposed as a nondirectional high-frequency loudspeaker. The spherical or hemispherical vibrator 2 is composed of a vibrating object 3 made up of a spherical or hemispherical piezoelectric material on the internal and external surfaces of which electrodes 4 and 4 are provided as shown in FIG. 5 and is driven by a driving mechanism 5, such as an amplifier, connected to the electrodes 4 and 4.
However, the conventional loudspeaker 1 exhibited an uneven sound pressure characteristic as shown in FIG. 6 because the sound pressure is intensified at the natural resonant frequency F0 of the resonator 2, and diminished at other frequencies.